1. Field of the Invention
The invention relates to a method and device for demounting/remounting hammers, hammer axles and/or protective caps of the rotors of hammer crushers, which are used in particular for comminuting of generally metallic scrap.
2. Description of the Related Art
Hammer crushers consist essentially of a housing with a rotor supported in the housing, with the rotor composed of a plurality of disks or spiders which are non-rotatably disposed on a shaft and hammers distributed between them. The hammers are rotatably supported on hammer axes that extend through the disks in a parallel-eccentric relationship to the shaft, wherein the hammer axes also hold protective caps which cover the rotor to protect the rotor against wear.
In the comminution process, the rotor and in particular the hammers, protective caps and the hammer axles holding the caps are subjected to the different wear conditions.
At least during the so-called maintenance intervals, wear may require that the spent hammers and/or protective caps are replaced by new ones. This is done by driving, pulling or pressing the hammer axles out of their seat in the disks or spiders.
For this purpose, devices with, for example, a hydraulic drive are used which represent an independent unit that can only be used during maintenance, but has otherwise no connection with the actual operation of the hammer crusher.
Depending on its operating mode, design and efficiency, such device which is typically referred to as a hammer axle pulling device, is important not only for changing hammers and protective caps of the hammer crusher, but also for an increased uptime of the hammer crusher.
Pulling the hammer axles can be difficult because the hammer axles are not only subjected to frictional wear, but also experience significant upsetting deformation. Accordingly, the hammer axles may have to be driven with very large forces through the bores of the disks or spiders, meaning that after its useful operating life, the respective hammer axle has both smaller and larger diameters as compared to the original manufacturing dimensions.
The hammer axle pulling devices used to date consist primarily of a moveable frame that can be moved manually, connecting rods secured to the frame and moveable thereto, which require significant space and are of complex design, so that the required maintenance has an unfavorable effect on the uptime of the hammer crusher system.
It is therefore the object of the invention to provide a method and a device, which simplifies demounting and remounting of hammers, hammer axles and/or protective caps in hammer crushers by eliminating the need for cross members and allowing a compact design of the device, by reducing manufacturing cost and by altering the sequence of steps required for demounting and remounting with the method to increase the uptime of the hammer crusher through reduced maintenance times.
The overall advantages of the invention and solution to the aforedescribed object of the invention are based on the fact that the method with the device can eliminate the use of pulling rods which reduces the required space for the pulling operation, so that the working platforms surrounding the hammer crusher, buildings and/or sound proofing walls can be set up closer to the hammer axle pulling device. Moreover, the drive can move the cross member close to the rotor, without requiring extensive manual labor for moving a carriage. Finally, the compact construction reduces manufacturing cost and investment expenses for building a hammer crusher, and the operating mode according to the invention increases the uptime of a hammer crusher plant.